Advanced Multiphysics Modelling Reduces Cost of Ownership of LED Production Equipment
Total Page：16
File Type：pdf, Size：1020Kb
fluid dynamics Advanced Multiphysics Modelling Reduces Cost of Ownership of LED Production Equipment AIXTRON AG, headquartered in Aachen, THE CHALLENGE Germany, is a leading provider of deposition equipment to the semiconductor industry. • Reducing the high manufacturing cost Established in 1983, the company's technology of LEDs to help accelerate widespread solutions are used by a diverse range of LED adoption customers worldwide to build advanced • Providing accurate control of layer components for electronic and opto-electronic composition and thickness of chemical applications based on compound, silicon, reactors and basic deposition process or organic semiconductor materials. These technology for MOVPE components in turn are used in fiber optic communication systems, wireless and mobile • Proving ability to reduce the cost Example of architectural lighting telephony applications, optical and electronic of ownership of LED production with white LEDs. storage devices, computing, signaling and equipment lighting, as well as a range of other leading-edge technologies. HIGH MANUFACTURING COST: KEY BARRIER TO T H E STO RY WIDESPREAD LED ADOPTION The lighting industry is experiencing a fundamental change as revolutionary as the introduction of “AIXTRON has used CFD-ACE+ for more digital cameras has been to photography. Light Emitting Diodes (LEDs), either based on compound than ten years for our modelling needs. semiconductors or novel organic polymers – referred to as OLEDs, Organic Light Emitting Diodes – The advanced multiphysics modelling are substantially more energy efficient in converting electricity into light, last longer, and are more capabitility of CFD-ACE+ helps evaluate versatile due to their small size than the traditional incandescent light bulb. In addition, LED lighting the impact of key process and reactor contributes to energy conservation and reduces CO2 emission. design parameters on performance The High Brightness LED market grew at an impressive 25-30% average annual growth rate from criteria like the uniformity of layer 2001 to 2006 and is expected to continue, with a market projection of $9 billion by 2011. In spite of thickness and composition on wafer recent productivity advances, the major roadblock to their widespread adoption remains the high and from wafer to wafer, the growth manufacturing cost of LEDs. efficiency and the robustness of the process. At AIXTRON, upfront modelling analysis has become an integral part of MODELLING AND SIMULATION OF THIN FILM any development project that involves DEPOSITION PROCESSES FOR MOVPE WITH the reaction chamber of an MOVPE ESI GROUP’S CFD-ACE+ MULTIPHYSICS reactor.” CFD SOFTWARE LEDs based on compound semiconductors are by far the most common type today, and are usually composed of multiple thin layers of so called III-V semiconductors. The method of choice for THE BENEFITS making LEDs is Metal Organic Vapour Phase Epitaxy (MOVPE), a deposition technique using gaseous metalorganic and hydride species. The precursors are supplied to the MOVPE reaction chamber • Aixtron reduced the cost of ownership with a flow of carrier gas at a process pressure below atmosphere, and the monocrystalline solid of production scale MOVPE reactors thin film is formed on heated substrates at temperatures from 600°C to 1400°C, depending on • Lowering the ownership cost of material and application. MOVPE reactors in turn reduced the AIXTRON AG develops, manufactures and markets chemical reactors and basic deposition process cost of LED manufacture technology for MOVPE, a highly precise chemical process used for the production of optoelectronic devices. The accurate control of layer composition and thickness, which can be as low as a few • Employing modelling and simulation is nanometers, with uniformity requirements on multiple substrates of less then +/- 1% deviation key to reducing the technological risk from the mean value, poses a formidable challenge to reaction chamber and process design. and the time-to-market for product Multiphysics modelling and simulation of semiconductor deposition processes has become an innovations indispensable tool to meet accuracy requirements of the sensitive MOVPE process. AIXTRON www.esi-group.com layers on the substrate surface. The models were developed in a joint collaboration with STR Inc. and incorporated into CFD-ACE+ via user subroutines and user defined scalars. The gas inlet of a MOVPE reactor chamber is one of the key components and essentially determines process performance and versatility. Primarily using a rigorous CFD based multiphysics modelling approach, a novel gas injector (figure 3) was developed for a new generation AIXTRON Planetary Reactor® with 42x2” wafers, which is currently the world’s largest production scale reactor for processing GaN based LEDs. The gas injector features multiple gas inlets for advanced Figure 1: The AIX 2800G4 HT Planetary Reactor® in 42x2” configuration deposition uniformity (bottom left) and the Crius 30x2” Close Coupled Showerhead Reactor control, symmetric and (bottom right) are integrated in the IC Platform system (top). uniform gas flow to guarantee wafer-to-wafer has been using ESI Group’s CFD-ACE+ multiphysics CFD software for reproducibility, and thermal nearly ten years to provide guidance during conceptualization, hardware control of the injector development and process tuning. Today’s industrial requirements to to prevent premature gas reduce the cost of LED manufacture call for production scale MOVPE phase reactions. reactors with lower cost of ownership. This goal is accomplished by larger and larger reaction chambers accommodating an increased number of Figure 2: Pressure dependence of GaN growth rate in the 6x2” Close wafers, reduced gas consumption per wafer area and increased through- Coupled Showerhead Reactor, comparing two different hardware sets, put at enhanced process performance. Modelling and simulation play (a) bare, cold showerhead and (b) covered warmer showerhead with a key role in reducing the technological risk and the time-to-market reduced chamber height. Model prediction (lines without symbols) and for product innovations. The impressive increase in reactor wafer experimental data (lines and symbols). load capacity over the past few years speaks for itself. Figure 1 shows AIXTRON’s flagship MOVPE reactors for the production of GaN based green, blue and white LEDs, the Planetary Reactor for 42x2” wafers (or 11x4” and 5x6” equivalently) and the Close Coupled Showerhead system for 30x2”. The modelling approach is based on the numerical computation of mixed convective laminar gas flow coupled with heat transfer and multi- component diffusive gas species transport. For the growth of group-III Nitrides this basic approach is supplemented by advanced mechanisms including complex gas phase reactions and even gas phase nucleation, i.e. the formation of nano-size particles by interaction between low volatile Figure 3: CFD modelling of a novel gas injector used in the AIXTRON reaction by-products, and the deposition of nitride semiconductor Planetary Reactor®. ABOUT ESI GROUP ESI is a world-leading supplier and pioneer of digital simulation software for prototyping and manufacturing processes that take into account the physics of materials. ESI has developed an extensive suite of coherent, industry-oriented applications to realistically simulate a product’s behavior during testing, to fine-tune manufacturing processes in accordance with desired product performance, and to evaluate the environment’s impact on product performance. ESI’s products represent a unique collaborative and open environment for Simulation-Based Design, enabling virtual prototypes to be improved in a continuous and collaborative manner while eliminating the need for physical prototypes during product development. The company employs over 750 high-level specialists worldwide covering more than 30 countries. ESI Group is listed in compartment C of NYSE Euronext Paris. For further information, visit www.esi-group.com. EUROPE BENELUX CZECH REPUBLIC FRANCE GERMANY ITALY SPAIN SWITZERLAND UNITED KINGDOM & SCANDINAVIA & EASTERN EUROPE ESI France ESI GmbH ESI Italia ESI Group Hispania Calcom ESI ESI UK ESI Group Netherlands MECAS ESI Parc d’Affaires Silic Mergenthalerallee 15-21 Via San Donato 191 Parque Empresarial Arroyo Parc Scientifique 1 Robert Robinson Av. Radex Innovation Centre Brojova 2113/16 99, rue des Solets - BP D-65760 Eschborn 40127 Bologna de la Vega EPFL / PSE-A The Magdalen Centre room 4.57 326 00 Pilsen 80112 Germany Italy C/ Francisca Delgado, 1015 Lausanne-EPFL Oxford Science Park [email protected] Rotterdamseweg 183 C Czech Republic 94513 Rungis cedex T. +49 (0)6196 9583 0 T. +39 0516335577 11 – planta 2ª Switzerland Oxford OX 4 4GA 2629 HD Delft T. +420 377 432 931 France F. +49 (0)6196 9583 111 T. +39 0516335578 28108 Alcobendas (Madrid) T. +41 21 693 2918 United Kingdom The Netherlands F. +420 377 432 930 T. +33 (0)1 49 78 28 00 F. +39 0516335601 Spain F. +41 21 693 4740 T. +44 (0) 1865 784 830 T. +31 (0)15 268 2501 F. +33 (0)1 46 87 72 02 T. +34 91 484 02 56 F. +44 (0) 1865 784 826 F. +31 (0)15 268 2514 F. +34 91 484 02 55 ESI Group AMERICAS ASIA Headquarters USA USA SOUTH AMERICA CHINA INDIA JAPAN KOREA SOUTH-EAST ASIA G/RO/09.86/A 100-102 Avenue de Suffren ESI North America ESI North America ESI South America ESI China ESI India ESI Japan Hankook ESI ESI Group South-East Asia 75015 Paris 32605 W 12 Mile Road 6767 Old Madison Pike Av. Pedroso de Morais, Room 16A, Indrakrupa #17, 100 feet 5F and 16F Shinjuku Green 157-033, 5F MISUNG 12, Jalan Dato Haji Harun, FRANCE Suite 350 Suite 600 1619 cj.312 Base F Fu Hua Mansion ring road Tower Bldg, 6-14-1, bldg., 660-6, Taman Taynton, Cheras Farmington Hills, MI Huntsville, AL 35806 São Paulo No. 8 Chaoyangmen 3rd phase, 6th block, Nishi-Shinjuku Deungchon-3Dong, 56000 Kuala Lumpur T. +33 (0)1 53 65 14 14 48334-3379 USA SP CEP 05419-001 North Avenue Banashankari 3rd stage Shinjuku-ku, Tokyo 160-0023 Gangseo-ku, Malaysia F. +33 (0)1 53 65 14 12 USA Brazil Beijing 100027 Bangalore 560 085 Japan Seoul T.